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| -rw-r--r-- | rfc822.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/rfc822.c b/rfc822.c new file mode 100644 index 00000000..02910dfc --- /dev/null +++ b/rfc822.c @@ -0,0 +1,322 @@ +/* + * rfc822.c -- code for slicing and dicing RFC822 mail headers + * + * Copyright 1996 by Eric S. Raymond + * All rights reserved. + * For license terms, see the file COPYING in this directory. + */ + +#include <stdio.h> +#include <ctype.h> +#include <string.h> +#if defined(STDC_HEADERS) +#include <stdlib.h> +#endif + +#include "fetchmail.h" + +void reply_hack(buf, host) +/* hack message headers so replies will work properly */ +char *buf; /* header to be hacked */ +const char *host; /* server hostname */ +{ + const char *from; + int parendepth, state = 0, tokencount = 0; + char mycopy[POPBUFSIZE+1]; + + if (strncmp("From: ", buf, 6) + && strncmp("To: ", buf, 4) + && strncmp("Reply-", buf, 6) + && strncmp("Cc: ", buf, 4) + && strncmp("Bcc: ", buf, 5)) { + return; + } + + strcpy(mycopy, buf); + for (from = mycopy; *from; from++) + { + switch (state) + { + case 0: /* before header colon */ + if (*from == ':') + state = 1; + break; + + case 1: /* we've seen the colon, we're looking for addresses */ + if (*from == '"') + state = 3; + else if (*from == '(') + { + parendepth = 1; + state = 4; + } + else if (*from == '<' || isalnum(*from)) + state = 5; + else if (isspace(*from)) + state = 2; + break; + + case 2: /* found a token boundary -- reset without copying */ + if (*from != ' ' && *from != '\t') + { + tokencount++; + state = 1; + --from; + continue; + } + + case 3: /* we're in a quoted human name, copy and ignore */ + if (*from == '"') + state = 1; + break; + + case 4: /* we're in a parenthesized human name, copy and ignore */ + if (*from == '(') + ++parendepth; + else if (*from == ')') + --parendepth; + if (parendepth == 0) + state = 1; + break; + + case 5: /* the real work gets done here */ + /* + * We're in something that might be an address part, + * either a bare unquoted/unparenthesized text or text + * enclosed in <> as per RFC822. + */ + /* if the address part contains an @, don't mess with it */ + if (*from == '@') + state = 6; + + /* If the address token is not properly terminated, ignore it. */ + else if (*from == ' ' || *from == '\t') + { + const char *cp; + + /* + * The only lookahead case. If we're looking at space or tab, + * we might be looking at a local name immediately followed + * by a human name. + */ + for (cp = from; isspace(*cp); cp++) + continue; + if (*cp == '(') + { + strcpy(buf, "@"); + strcat(buf, host); + buf += strlen(buf); + state = 1; + } + } + + /* + * On proper termination with no @, insert hostname. + * Case '>' catches <>-enclosed mail IDs. Case ',' catches + * comma-separated bare IDs. + */ + else if (strchr(">,", *from)) + { + strcpy(buf, "@"); + strcat(buf, host); + buf += strlen(buf); + tokencount = 0; + state = 1; + } + + /* a single local name alone on the line */ + else if (*from == '\n' && tokencount == 1) + { + strcpy(buf, "@"); + strcat(buf, host); + buf += strlen(buf); + state = 2; + } + + /* everything else, including alphanumerics, just passes through */ + break; + + case 6: /* we're in a remote mail ID, no need to append hostname */ + if (*from == '>' || *from == ',' || isspace(*from)) + state = 1; + break; + } + + /* all characters from the old buffer get copied to the new one */ + *buf++ = *from; + } + *buf++ = '\0'; +} + +char *nxtaddr(hdr) +/* parse addresses in succession out of a specified RFC822 header */ +const char *hdr; /* header to be parsed, NUL to continue previous hdr */ +{ + static char *tp, address[POPBUFSIZE+1]; + static const char *hp; + static int state; + int parendepth; + + /* + * Note 1: RFC822 escaping with \ is *not* handled. Note 2: it is + * important that this routine not stop on \r, since we use \r as + * a marker for RFC822 continuations elsewhere. + */ + + if (hdr) + { + hp = hdr; + state = 0; + } + + for (; *hp; hp++) + { + switch (state) + { + case 0: /* before header colon */ + if (*hp == '\n') + { + state = 6; + return(NULL); + } + else if (*hp == ':') + { + state = 1; + tp = address; + } + break; + + case 1: /* we've seen the colon, now grab the address */ + if (*hp == '\n') /* end of address list */ + { + *tp++ = '\0'; + state = 6; + return(tp = address); + } + else if (*hp == ',') /* end of address */ + { + if (tp > address) + { + *tp++ = '\0'; + ++hp; + return(tp = address); + } + } + else if (*hp == '"') /* quoted string */ + { + state = 2; + *tp++ = *hp; + } + else if (*hp == '(') /* address comment -- ignore */ + { + parendepth = 1; + state = 3; + } + else if (*hp == '<') /* begin <address> */ + { + state = 4; + tp = address; + } + else if (isspace(*hp)) /* ignore space */ + state = 1; + else /* just take it */ + { + state = 1; + *tp++ = *hp; + } + break; + + case 2: /* we're in a quoted string, copy verbatim */ + if (*hp == '\n') + { + state = 6; + return(NULL); + } + if (*hp != '"') + *tp++ = *hp; + else if (*hp == '"') + { + *tp++ = *hp; + state = 1; + } + break; + + case 3: /* we're in a parenthesized comment, ignore */ + if (*hp == '\n') + return(NULL); + else if (*hp == '(') + ++parendepth; + else if (*hp == ')') + --parendepth; + if (parendepth == 0) + state = 1; + break; + + case 4: /* possible <>-enclosed address */ + if (*hp == '>') /* end of address */ + { + *tp++ = '\0'; + state = 1; + ++hp; + return(tp = address); + } + else if (*hp == '<') /* nested <> */ + tp = address; + else if (*hp == '"') /* quoted address */ + { + *tp++ = *hp; + state = 5; + } + else /* just copy address */ + *tp++ = *hp; + break; + + case 5: /* we're in a quoted address, copy verbatim */ + if (*hp == '\n') /* mismatched quotes */ + { + state = 6; + return(NULL); + } + if (*hp != '"') /* just copy it if it isn't a quote */ + *tp++ = *hp; + else if (*hp == '"') /* end of quoted string */ + { + *tp++ = *hp; + state = 4; + } + break; + + case 6: /* after last address */ + return(NULL); + break; + } + } + + return(NULL); +} + +#ifdef TESTMAIN +main(int argc, char *argv[]) +{ + char buf[POPBUFSIZE], *cp; + + while (fgets(buf, sizeof(buf)-1, stdin)) + { + if (strncmp("From: ", buf, 6) + && strncmp("To: ", buf, 4) + && strncmp("Reply-", buf, 6) + && strncmp("Cc: ", buf, 4) + && strncmp("Bcc: ", buf, 5)) + continue; + else + if ((cp = nxtaddr(buf)) != (char *)NULL) + do { + printf("Address: %s\n", cp); + } while + ((cp = nxtaddr((char *)NULL)) != (char *)NULL); + + } +} +#endif /* TESTMAIN */ + +/* rfc822.c end */ |